Supercritical Infusion

Certain inorganic crystalline materials can be infused into organic or polymeric substrates (in solid phase) in a supercritical fluid medium. Further, organic ingredients that are insoluble in the substrate can also be infused similarly using a supercritical fluid medium. Such a process is quite significant and invaluable, when a temperature sensitive ingredient has to be added into other substrate, such as polymeric resin or film. Infused products by supercritical infusion are superior in quality and desired functions, compared to melt-processed counterparts which are prone to have annealed, fused, and agglomerated morphology. Application fields are quite broad from pharmaceuticals, biomedical applications, multifunctional films, adding colorants or tints to the finished goods, controlled release materials, etc. The process can also be readily modified as or expanded to encapsulation.  Lee’s original work in collaboration with IMET Corporation and Northern Technologies International Corporation (NTIC) has received a couple of U.S. patents for infusion of alkali metal crystals [such as volatile corrosion inhibitor (VCI) ingredients] into preformed polymeric articles.

• M. Gencer, S. Lee, A. Sardesai, and D. Kubik, “Process for Infusing an Alkali Metal Nitrite into a Synthetic Resinous Material”, U.S. Patent No. 7,217,749, May 15, 2007.
• M. Gencer, S. Lee, A. Sardesai, and D. Kubik, “Process for Incorporating One or More Materials into a Polymer Composition and Products Produced Thereby”, U.S. Patent No. 7,217,750, May 15, 2007.

Lee’s R&D team has investigated and elucidated the mechanic steps and processes of supercritical infusion of salt crystals into thermoplastic polymer resins and preformed films. The effectiveness of supercritical infusion process was demonstrated in terms of the final product quality in desired functions, lower temperature processing, uniform dispersion, reduction in raw material cost, etc. A wide range of applications are being explored for manufacturing multi-functional value-added superior-quality materials.